Tiny green grey shelled things?

[vicegripjim]

So I spotted a couple of these and they didn't seem to be causing any trouble, but the population is exploding now and now I just wanna make sure. Little shelled dudes are about 3-5mm in diameter, green/grey in colouration.

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[Jekyl]

Stomatella?

 

[Sophie"s mom]

possibly limpets

 

[ISpeakForTheSeas]

Those are keyhole limpets - generally harmless/beneficial, but a small number of species are known to eat SPS:

It’s rare, but there are two taxonomic subfamilies of keyhole limpets (Diodorinae and Emarginulinae) that I have found research on showing that they have a handful of species in them that are either known to or thought to occasionally eat corals (I’d need to go digging through the papers again, but, IIRC, they only ate SPS , and they had pretty specific tastes/preferences). One example:

Edit: just to reinforce, regular limpets are fine, and most keyhole limpets (including most from the subfamilies listed above) are reef safe; to the best of current scientific knowledge, only a very small number of them are not.

Diodora galeata was the example above.

 

[EeyoreIsMySpiritAnimal]

Limpets

 

[4theluvofcoral]

So I spotted a couple of these and they didn't seem to be causing any trouble, but the population is exploding now and now I just wanna make sure. Little shelled dudes are about 3-5mm in diameter, green/grey in colouration.

.

Look like some type of limpet to me.